The sides had battled out a tense 90 minutes before 22-year-old Republic of Ireland defender O’Dea scored to give Celtic the lead just seconds into extra-time.

Aiden McGeady then won and converted a penalty to make it 2-0 in the final seconds as Kirk Broadfoot was sent off.

With only four derby finals in the last 20 years, the match was an occasion to be savoured.

Yet, although Gordon Strachan admitted before the game that both sides had a ‘responsibility to try and entertain’, the Celtic line-up had appeared to put the emphasis on defence.

As Strachan had said ahead of the game, “The teams right now will say, ‘We want to win it’, but they probably fear getting beat more” and, after the dismal 0-0 draw when the sides met in the league last month, there were fears of another lacklustre display.

In the event, there was plenty of attacking intent but little to show for it in the opening 25 minutes.

However, for a five-minute spell, Celtic started to find plenty of gaps and they looked certain to open the scoring.

Scott Brown had the first real chance, firing just over on 26 minutes from distance, and Glenn Loovens headed wide from a good position shortly afterwards.

Aiden McGeady then pulled clear down left on 31 minutes and was able to pick out Brown, but the Scotland midfielder was unable to keep his shot down from close range.

The Hoops were unable to capitalise on that dominance, though, and Kyle Lafferty began to look increasingly dangerous up front for Rangers.

He came very close to giving Walter Smith’s men the advantage just before half-time, too, when he controlled the ball on his chest on the edge of the area and then fired just over the bar.

Rangers started the second half the stronger as well, and Steven Davis – disappointing in the first half – was at the heart of much of their attacking play.

They nearly took the lead on the hour when Artur Boruc received a backpass and attempted a Cruyff turn to avert the danger as Lafferty closed in. In the end, he was very fortunate not to cost his side a goal.

With McGeady, Brown and Shunsuke Nakamura all starting to get into gear, though, Celtic provided a response, but it was, uncharacteristically, a Glenn Loovens header on 70 minutes that caused the most problems, with Pedro Mendes having to defend the ball on the line.

By the end of the 90 minutes, both sides had had several half-chances, Celtic had brought on Georgios Samaras to support Scott McDonald and Rangers had replaced Lafferty and Kenny Miller with Kris Boyd and Nacho Novo, but neither side was able to find that cutting-edge.

But whatever Strachan had said to his team appeared to have worked as, less than 60 seconds into extra-time, Celtic were in front as young defender Darren O’Dea headed home Nakamura’s free-kick in a crowded penalty area.

Scott McDonald then hopelessly failed to double their advantage as he went clean through, while Samaras and Brown also went close with good efforts from the edge of the area. Samaras then raced clean through but failed to beat Allan McGregor.

Rangers started to reassert themselves in the second period of extra-time, but they struggled to find a way through and, even in the dying seconds, Celtic always looked fairly comfortable.

And, with 122 minutes on the clock, McGeady raced clear into the Rangers box only to be hauled down by Broadfoot, who was dismissed before McGeady confidently dispatched the spot kick.

It was a disappointing end for Walter Smith after his side had matched their opponents during the 90 minutes, but there was no doubting which side deserved the victory after 120.